Multi-cast resource allocation by aggregation level

ABSTRACT

Multicasting resource allocation information per aggregation level is enabled. A device allocates resources to UEs according to aggregation level. At each level, a control message includes a bitmap, where each bit corresponds to a different resource, an array, and an ID field for dynamic mapping to the bitmap. The placement order value of an ID in the field is stored at locations in the array. The index value for those locations in the array identifies which asserted bits in the bitmap correspond to the resource allocation for a UE at the level. The control message is multicast to the UEs specified at the aggregation level. The bitmap may have the same length at each level, or have reducing length at lower levels with the removal of bits already asserted at higher levels. The UE reconstructs the bitmap from the higher level bitmaps and the bitmap for the current level.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims priority to and the benefit of the U.S.Provisional Patent Application No. 62/293,656, filed Feb. 10, 2016,which is hereby incorporated by reference in its entirety as if fullyset forth below in its entirety and for all applicable purposes.

TECHNICAL FIELD

Aspects of the present disclosure relate generally to wirelesscommunication systems, and more particularly, to multi-cast resourceallocation information using aggregation level-based multi-cast controlchannel design.

INTRODUCTION

In wireless communication networks, resources (e.g., symbol, frequency,and/or code resources) are allocated to a user equipment (UE) and thencommunicated to that UE via downlink control channels (e.g., via thephysical downlink control channel, or PDCCH). Presently, allocationinformation specific to the UE (e.g., modulation coding scheme (MCS),resource allocation type, coding rate, resource elements, etc.) issignaled to the UE with downlink control information (DCI) messages thatare specific to the UE. Thus, as more UEs come in use in a given area,the scheduling and overhead demands for signaling that schedulingincreases.

As a result, there is a need for techniques to allow resource allocationinformation to be signaled to UEs in a manner that reduces the overheadto do so as well as improves the efficiency.

BRIEF SUMMARY OF SOME EXAMPLES

The following summarizes some aspects of the present disclosure toprovide a basic understanding of the discussed technology. This summaryis not an extensive overview of all contemplated features of thedisclosure, and is intended neither to identify key or critical elementsof all aspects of the disclosure nor to delineate the scope of any orall aspects of the disclosure. Its sole purpose is to present someconcepts of one or more aspects of the disclosure in summary form as aprelude to the more detailed description that is presented later.

In one aspect of the disclosure, a method is provided that includesgenerating, by an access point, a first downlink control messagecomprising a first set of resource allocations to a first plurality ofwireless communications devices based on the first plurality of wirelesscommunications devices being assigned to a first aggregation level. Themethod further includes generating, by the access point, a seconddownlink control message comprising a second set of resource allocationsto a second plurality of wireless communications devices based on thesecond plurality of wireless communications devices being assigned to asecond aggregation level that is different from the first aggregationlevel. The method further includes transmitting, from the access point,the first downlink control message to the first plurality of wirelesscommunications devices and the second downlink control message to thesecond plurality of wireless communications devices.

In an additional aspect of the disclosure, a method is provided thatincludes receiving, at a wireless communications device, a multicastdownlink control message sent to a plurality of wireless communicationsdevices including the wireless communications device according to afirst aggregation level from an access point. The method furtherincludes extracting, by the wireless communications device, a resourceallocation by the access point for the wireless communications devicefrom among a plurality of resource allocations to the plurality ofwireless communications devices in the multicast downlink controlmessage. The method further includes wherein the first aggregation levelis one from among a plurality of different aggregation levels, theresource allocation based on the wireless communications device beingassigned to the aggregation level.

In an additional aspect of the disclosure, an apparatus is provided thatincludes a processor configured to generate a first downlink controlmessage comprising a first set of resource allocations to a firstplurality of wireless communications devices based on the firstplurality of wireless communications devices being assigned to a firstaggregation level. The processor is further configured to generate asecond downlink control message comprising a second set of resourceallocations to a second plurality of wireless communications devicesbased on the second plurality of wireless communications devices beingassigned to a second aggregation level that is different from the firstaggregation level. The apparatus further includes a transceiverconfigured to transmit the first downlink control message to the firstplurality of wireless communications devices and the second downlinkcontrol message to the second plurality of wireless communicationsdevices.

In an additional aspect of the disclosure, an apparatus is provided thatincludes a transceiver configured to receive a multicast downlinkcontrol message to a plurality of wireless communications devicesincluding the apparatus according to an aggregation level from an accesspoint. The apparatus further includes a processor configured to extracta resource allocation by the access point for the apparatus from among aplurality of resource allocations to the plurality of wirelesscommunications devices in the multicast downlink control message. Theapparatus further includes wherein the aggregation level is one fromamong a plurality of different aggregation levels, the resourceallocation based on the wireless communications device being assigned tothe aggregation level.

In an additional aspect of the disclosure, a computer readable mediumhaving program code recorded thereon is provided, the program codeincluding code for causing an access point to generate a first downlinkcontrol message comprising a first set of resource allocations to afirst plurality of wireless communications devices based on the firstplurality of wireless communications devices being assigned to a firstaggregation level. The program code further includes code for causingthe access point to generate a second downlink control messagecomprising a second set of resource allocations to a second plurality ofwireless communications devices based on the second plurality ofwireless communications devices being assigned to a second aggregationlevel that is different from the first aggregation level. The programcode further includes code for causing the access point to transmit thefirst downlink control message to the first plurality of wirelesscommunications devices and the second downlink control message to thesecond plurality of wireless communications devices.

In an additional aspect of the disclosure, a computer readable mediumhaving program code recorded thereon is provided, the program codeincluding code for causing a wireless communications device to receive amulticast downlink control message to a plurality of wirelesscommunications devices including the wireless communications deviceaccording to an aggregation level from an access point. The program codefurther includes code for causing the wireless communications device toextract a resource allocation by the access point for the wirelesscommunications device from among a plurality of resource allocations tothe plurality of wireless communications devices in the multicastdownlink control message. The program code further includes wherein theaggregation level is one from among a plurality of different aggregationlevels, the resource allocation based on the wireless communicationsdevice being assigned to the aggregation level.

In an additional aspect of the disclosure, an apparatus is provided thatincludes means for generating a first downlink control messagecomprising a first set of resource allocations to a first plurality ofwireless communications devices based on the first plurality of wirelesscommunications devices being assigned to a first aggregation level. Theapparatus further includes means for generating a second downlinkcontrol message comprising a second set of resource allocations to asecond plurality of wireless communications devices based on the secondplurality of wireless communications devices being assigned to a secondaggregation level that is different from the first aggregation level.The apparatus further includes means for transmitting the first downlinkcontrol message to the first plurality of wireless communicationsdevices and the second downlink control message to the second pluralityof wireless communications devices.

In an additional aspect of the disclosure, an apparatus is provided thatincludes means for receiving a multicast downlink control message to aplurality of wireless communications devices including the apparatusaccording to an aggregation level from an access point. The apparatusfurther includes means for extracting a resource allocation by theaccess point for the apparatus from among a plurality of resourceallocations to the plurality of wireless communications devices in themulticast downlink control message. The apparatus further includeswherein the aggregation level is one from among a plurality of differentaggregation levels, the resource allocation based on the wirelesscommunications device being assigned to the aggregation level.

Other aspects, features, and embodiments of the present invention willbecome apparent to those of ordinary skill in the art, upon reviewingthe following description of specific, exemplary embodiments of thepresent invention in conjunction with the accompanying figures. Whilefeatures of the present invention may be discussed relative to certainembodiments and figures below, all embodiments of the present inventioncan include one or more of the advantageous features discussed herein.In other words, while one or more embodiments may be discussed as havingcertain advantageous features, one or more of such features may also beused in accordance with the various embodiments of the inventiondiscussed herein. In similar fashion, while exemplary embodiments may bediscussed below as device, system, or method embodiments it should beunderstood that such exemplary embodiments can be implemented in variousdevices, systems, and methods.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary wireless communication environmentaccording to embodiments of the present disclosure.

FIG. 2 is a block diagram of an exemplary wireless communication deviceaccording to embodiments of the present disclosure.

FIG. 3 is a block diagram of an exemplary wireless communication deviceaccording to embodiments of the present disclosure.

FIG. 4A is a block diagram of an exemplary downlink frame structureaccording to embodiments of the present disclosure.

FIG. 4B is a block diagram of an exemplary downlink control messagestructure according to embodiments of the present disclosure.

FIG. 4C is a block diagram of an exemplary downlink control messagestructure according to embodiments of the present disclosure.

FIG. 5A is a flowchart illustrating bitmap structure per aggregationlevel according to embodiments of the present disclosure.

FIG. 5B is a flowchart illustrating bitmap structure per aggregationlevel according to embodiments of the present disclosure.

FIG. 6 is a flowchart illustrating an exemplary method for wirelesscommunication in accordance with various aspects of the presentdisclosure.

FIG. 7 is a flowchart illustrating an exemplary method for wirelesscommunication in accordance with various aspects of the presentdisclosure.

DETAILED DESCRIPTION

The detailed description set forth below, in connection with theappended drawings, is intended as a description of variousconfigurations and is not intended to represent the only configurationsin which the concepts described herein may be practiced. The detaileddescription includes specific details for the purpose of providing athorough understanding of the various concepts. However, it will beapparent to those skilled in the art that these concepts may bepracticed without these specific details. In some instances, well-knownstructures and components are shown in block diagram form in order toavoid obscuring such concepts.

The techniques described herein may be used for various wirelesscommunication networks such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, LTEnetworks, GSM networks, and other networks. The terms “network” and“system” are often used interchangeably. A CDMA network may implement aradio technology such as Universal Terrestrial Radio Access (UTRA),cdma2000, etc. UTRA includes Wideband CDMA (WCDMA) and other variants ofCDMA. CDMA2000 covers IS-2000, IS-95, and IS-856 standards. A TDMAnetwork may implement a radio technology such as Global System forMobile Communications (GSM). An OFDMA network may implement a radiotechnology such as Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB),IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-DI-DMA,etc. UTRA and E-UTRA are part of Universal Mobile TelecommunicationSystem (UMTS). 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A)are new releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-Aand GSM are described in documents from an organization named “3rdGeneration Partnership Project” (3GPP). CDMA2000 and UMB are describedin documents from an organization named “3rd Generation PartnershipProject 2” (3GPP2). The techniques described herein may be used for thewireless networks and radio technologies mentioned above as well asother wireless networks and radio technologies, such as a nextgeneration (e.g., 5th Generation (5G)) network.

Further, devices may also communicate with one another using variouspeer-to-peer technologies such as LTE-Direct (LTE-D), Bluetooth,Bluetooth Low Energy (BLE), ZigBee, radiofrequency identification(RFID), and/or other ad-hoc or mesh network technologies. Embodiments ofthis disclosure are directed to any type of modulation scheme that maybe used on any one or more of the above-recited networks and/or thoseyet to be developed.

Embodiments of the present disclosure introduce systems and techniquesto multi-cast resource allocation information using aggregationlevel-based multi-cast control channel design. In an embodiment, ascheduler (such as a base station) may allocate resource elements (e.g.,for downlink and/or uplink) to one or more UEs according to aggregationlevel, instead of per UE. To accomplish this, a base station may groupUEs according to their aggregation levels and generate a multi-castdownlink control message, where each multi-cast message is sent to thoseUEs that are aggregated into that group, such that a first multi-castmessage is sent to a first group of UEs at a first aggregation level anda second multi-cast message is sent to a second group of UEs at a secondaggregation level, etc. The UEs may not know beforehand which group theyare aggregated into by the base station, resulting in dynamicaggregation level grouping.

When the base station determines the UEs that are to be scheduled at acertain aggregation level, the base station identifies each availableresource in a bitmap, where each bit in the bitmap corresponds to adifferent resource available for scheduling. The base station assertsthose bits in the bitmap that correspond to resources to be allocated toUEs in that aggregation level. The base station also creates an arraythat is equal in length to the number of bits asserted in the bitmap forthe aggregation level. The array provides a dynamic mapping between theidentifiers of the UEs in the aggregation level and the asserted bits inthe bitmap, so that less space may be used to establish the allocations.

The base station also creates a UE identifier list that lists each UEscheduled and allocated resources at the aggregation level. Theplacement order values from the UE identifier list is the value storedin specific array elements. When a UE searches the array for theplacement order value of its particular UE identifier, the index valuesassociated with the array elements where the placement order values arelocated are used to identify which asserted bits have been allocated tothat UE. Thus, the index value specifies how many asserted bits in thebitmap corresponds to the asserted bit (and resource) assigned to theUE. This information is included in the downlink control message andmulticast to the UEs.

The UE receives the downlink control message per aggregation level, andfollows an order (e.g., the reverse order) to access the mapping to theallocated resources. In some embodiments, the bitmap size for eachaggregation level is kept the same, so that the UEs at each aggregationlevel have clear access to the bitmap-resource associations. In otherembodiments, the bitmap size for each aggregation level decreases downeach level. The decrease results from the bits asserted in the upperaggregation levels being removed for transmission of the bitmap at thecurrent aggregation level. The UEs listen to upper aggregation levels aswell as their own to obtain a full view of the bitmap, thus reducing thetransmission size overhead while still allowing the UEs to have theappropriate information to obtain their resource allocations.

FIG. 1 illustrates a wireless communication network 100 in accordancewith various aspects of the present disclosure. The wirelesscommunication network 100 may include a number of UEs 102, as well as anumber of base stations 104. The base stations 104 may include anevolved Node B (eNodeB). A base station 104 may also be referred to asan access point, base transceiver station, a node B, eNB, etc. A basestation 104 may be a station that communicates with the UEs 102.

The base stations 104 communicate with the UEs 102 as indicated bycommunication signals 106. A UE 102 may communicate with the basestation 104 via an uplink and a downlink. The downlink (or forward link)refers to the communication link from the base station 104 to the UE102. The uplink (or reverse link) refers to the communication link fromthe UE 102 to the base station 104. The base stations 104 may alsocommunicate with one another, directly or indirectly, over wired and/orwireless connections, as indicated by communication signals 108.

UEs 102 may be dispersed throughout the wireless network 100, as shown,and each UE 102 may be stationary or mobile. The UE 102 may also bereferred to as a terminal, a mobile station, a subscriber unit, etc. TheUE 102 may be a cellular phone, a smartphone, a personal digitalassistant, a wireless modem, a laptop computer, a tablet computer, adrone, an entertainment device, a hub, a gateway, an appliance, awearable, peer-to-peer and device-to-device components/devices(including fixed, stationary, and mobile), Internet of Things (IoT)components/devices, and Internet of Everything (IoE) components/devices,etc. The wireless communication network 100 is one example of a networkto which various aspects of the disclosure apply.

Each base station 104 may provide communication coverage for aparticular geographic area. In 3GPP, the term “cell” can refer to thisparticular geographic coverage area of a base station and/or a basestation subsystem serving the coverage area, depending on the context inwhich the term is used. In this regard, a base station 104 may providecommunication coverage for a macro cell, a pico cell, a femto cell,and/or other types of cell. A macro cell generally covers a relativelylarge geographic area (e.g., several kilometers in radius) and may allowunrestricted access by UEs with service subscriptions with the networkprovider. A pico cell would generally cover a relatively smallergeographic area and may allow unrestricted access by UEs with servicesubscriptions with the network provider. A femto cell would alsogenerally cover a relatively small geographic area (e.g., a home) and,in addition to unrestricted access, may also provide restricted accessby UEs having an association with the femto cell (e.g., UEs in a closedsubscriber group (CSG), UEs for users in the home, and the like). A basestation for a macro cell may be referred to as a macro base station. Abase station for a pico cell may be referred to as a pico base station.And, a base station for a femto cell may be referred to as a femto basestation or a home base station. In the example shown in FIG. 1, the basestations 104 a, 104 b and 104 c are examples of macro base station forthe coverage areas 110 a, 110 b and 110 c, respectively (also referredto as cells herein). The base stations 104 d and 104 e are examples ofpico and/or femto base stations for the coverage areas 110 d and 110 e,respectively. A base station 104 may support one or multiple (e.g., two,three, four, and the like) cells.

The wireless communication network 100 may also include relay stations.A relay station is a station that receives a transmission of data and/orother information from an upstream station (e.g., a base station, a UE,or the like) and sends a transmission of the data and/or otherinformation to a downstream station (e.g., another UE, another basestation, or the like). A relay station may also be a UE that relaystransmissions for other UEs. A relay station may also be referred to asa relay base station, a relay UE, a relay, and the like. Some relays mayalso have UE capabilities/functionalities .

The wireless communication network 100 may support synchronous orasynchronous operation. For synchronous operation, the base stations 104may have similar frame timing, and transmissions from different basestations 104 may be approximately aligned in time. For asynchronousoperation, the base stations 104 may have different frame timing, andtransmissions from different base stations 104 may not be aligned intime.

In some implementations, the wireless communication network 100 utilizesorthogonal frequency division multiplexing (OFDM) on the downlink andsingle-carrier frequency division multiplexing (SC-FDM) on the uplink.OFDM and SC-FDM partition the system bandwidth into multiple (K)orthogonal subcarriers, which are also commonly referred to as tones,bins, or the like. Each subcarrier may be modulated with data. Ingeneral, modulation symbols are sent in the frequency domain with OFDMand in the time domain with SC-FDM. The spacing between adjacentsubcarriers may be fixed, and the total number of subcarriers (K) may bedependent on the system bandwidth. For example, K may be equal to 72,180, 300, 600, 900, and 1200 for a corresponding system bandwidth of1.4, 3, 5, 10, 15, or 20 megahertz (MHz), respectively. The systembandwidth may also be partitioned into sub-bands. For example, asub-band may cover 1.08 MHz, and there may be 1, 2, 4, 8 or 16 sub-bandsfor a corresponding system bandwidth of 1.4, 3, 5, 10, 15, or 20 MHz,respectively.

According to embodiments of the present disclosure, resource allocationinformation for one or more UEs 102 is multicast to the UEs 102 perresource block, instead of individual transmissions per UE 102,according to the aggregation levels to which the different UEs 102 aregrouped (e.g., dynamically by the base station 104). As used herein, anaggregation level refers to a mechanism by which wireless communicationssystems (e.g., LTE, LTE-A, etc.) may map downlink control information(DCI, also referred to herein as DCI messages or downlink controlmessages) to downlink control symbols. In particular, the aggregationlevel determines how many downlink resource elements in the controlchannel (e.g., control channel elements (CCEs) in the PDCCH) are used tosend the DCI messages. In an embodiment, there may be 4 aggregationlevels identified as aggregation levels 1, 2, 4, and 8.

As an example, each CCE may represent a group of resource elements that,in an embodiment, may include four resource elements (e.g.,subcarriers). Further, each resource element (e.g., subcarrier) maysupport mapping 2 bits. As an example, a CCE may be a group of 9resource element groups, so that a given CCE corresponds to a total of36 resource elements (9 groups*4 resource elements per group) that canmap a total of 72 bits (36 resource elements*2 bits per element). Eachaggregation level may be associated with a different number of CCEs.

For example, aggregation level 1 may be associated with 1 CCE, meaningthat a total of 72 bits may be available for mapping for a DCI. Asanother example, aggregation level 2 may be associated with 2 CCEs,meaning that a total of 144 bits (2 CCEs*36 resource elements*2 bits perelement) may be available for mapping for a DCI after applying a coderate to the DCI. As another example, aggregation level 4 may beassociated with 4 CCEs, meaning that a total of 288 bits (4 CCEs*36resource elements*2 bits per element) may be available for mapping for aDCI after applying a code rate to the DCI. As another example,aggregation level 8 may be associated with 8 CCEs, meaning that a totalof 576 bits (8 CCEs*36 resource elements*2 bits per element) may beavailable for mapping for a DCI after applying a code rate to the DCI.These are for illustration only. Other combinations may be defined andremain within the scope of the present disclosure. Further, as usedherein, the aggregation levels may be selected based on environmentconditions. For example, aggregation level 8 may be selected where someenvironment metric, such as signal-to-noise ratio (SNR), issignificantly low, and be referred to as the highest aggregation level(where 8 is highest; if other levels come out that utilize more CCEs andthus can pack more bits, those would then receive the designation of“highest”). Where SNR is better, “lower” aggregation levels such as 4 or2 (in that order from higher to lower) may be used. Where SNR is best,the “lowest” aggregation level (e.g., aggregation level 1 in the presentexample) may be used.

According to embodiments of the present disclosure, a scheduler (e.g.,associated with a base station 104) may perform one or more operationsrelated to allocating resource elements for transmitting and receivingdata with UEs 102. Resource elements that may be scheduled includeresource blocks (RBs), resource block groups (RBGs), and/or any othertype of resource suitable for embodiments of the present disclosure. Thescheduler determines which aggregation level to use for a given DCIformat (e.g., downlink formats such as 1, 1A, 1B, 1C, 1D, 2, and 2A anduplink formats such as 0, 3, and 3A to name some examples; forsimplicity of discussion, herein reference will be made generally todownlink formats though embodiments of the present disclosure may beapplicable to both downlink and uplink formats). The scheduler may do sobased upon different information, such as channel quality and/or UEidentifier type. For example, if UE 102 has reported a poor channelquality, the scheduler may determine to use a more robustly coded DCI(e.g., rate matching bits, adding additional bits/redundancy checks toprovider better forward error correction protection for the actual bitsof the message, e.g. a set of bits for the message and additional bitsfor a cyclic redundancy check (CRC)). This would increase the bit lengthof the DCI, and therefore the scheduler may select a higher aggregationlevel to accommodate that length and desired level of robustness. TheDCI messages may be used to signal resource allocation information suchas modulation coding scheme (MCS), resource allocation type, codingrate, resource elements, etc.

Instead of sending the scheduled information (e.g., resource allocationinformation) via multiple unicast messages to the different UEs 102, asis normally the situation for dedicated UE identifiers, the schedulermay send multicast messages according to one or more aggregation levels.In particular, DCI messages for dedicated UE identifiers (e.g., cellradio network temporary identifier, or C-RNTI; this is exemplary only,as other types of identifiers could be used as well) may, according toembodiments of the present disclosure, be multicast to multiple UEs thathave been grouped together per aggregation level. Further, grouping maybe performed dynamically such that the UEs 102 are unaware of theirgroup assignments before the messages are multicast.

For example, referring again to FIG. 1, the wireless communicationnetwork 100 includes multiple UEs 102 in communication with thedifferent base stations 104. For example, in cell 110 a, UEs 102 a and102 b receive coverage from base station 104 c. As illustrated, they areboth near the edge of the cell 110 a, and therefore may have lower SNR.As a result, the scheduler may schedule downlink control messages (thatmay identify scheduled PDSCH and/or PUSCH resources, for example) forboth in higher aggregation levels, whether the same or different (e.g.,one or both in aggregation levels 8 or 4, or some combination thereof).SNR may be affected by additional environmental factors than distance,and therefore even UEs 102 closer in distance to a given base station104 may still be scheduled for downlink control messages at a higheraggregation level.

As another example, UEs 102 a, 102 c, 102 d, and 102 e are within thecell 110 b and receive coverage from the base station 104 b. Given theirrespective SNRs (and/or other channel quality information and/orpriorities), the base station 104 b may schedule the downlink controlmessages for the UEs 102 c and 102 e in a first aggregation level (e.g.,4) and the UEs 102 a and 102 d in a second aggregation level (e.g., 8)that is higher than the first aggregation level. As another example, UEs102 a, 102 c, 102 g , 102 h , and 102 i are within the cell 110 c andreceive coverage from the base station 104 a. The base station 104 c mayschedule the downlink control messages for the UEs 102 a and 102 i at ahighest aggregation level (e.g., 8), the UE 102 c in a second, loweraggregation level (e.g., 4), the UE 102 h in a third, lower aggregationlevel (e.g., 2), and the UE 102 g in a lowest aggregation level (e.g.,1), based on their respective channel quality measurements. As will berecognized, these are exemplary for ease of illustration only.

Continuing with this illustration and focusing on cell 110 c inparticular, when scheduling the downlink control messages for the UEs102 a, 102 c, 102 g , 102 h , and 102 i, the base station 104 c mayperform different aspects of embodiments of the present disclosure. Forexample, having determined to schedule the downlink control messages forthe UEs in different aggregation levels, the base station 104 c mayproceed with generating downlink control messages for the respectiveaggregation levels. Thus, having determined to schedule the downlinkcontrol messages for the UEs 102 a and 102 i in the highest aggregationlevel, the base station 104 c may proceed with generating the downlinkcontrol message according to the selected aggregation level. A singledownlink control message may provide resource allocation information(whether downlink or uplink, but downlink in this example).

According to embodiments of the present disclosure, the scheduler (here,base station 104 c) may identify each available resource element, suchas per RBG, and maintain/provide a bitmap where each bit corresponds toa different available RBG (the level of granularity used herein, thoughother levels of granularity may be similarly used). For example, thebitmap may be of a length that corresponds to the number of RBGsavailable for a given system bandwidth (e.g., 50 bits long for a 10 MHzsystem bandwidth, though other lengths are possible ranging from 10 bitsor less to over 200 as just one example). The value of each bit mayidentify whether the RBG corresponding to that bit is scheduled ornot—for example, a 0 may indicate the RBG has not been scheduled, whilea 1 (also referred to as asserted herein) may indicate the RBG has beenscheduled. Since each bit corresponds to a different RBG, and the UEs102 have knowledge of the correspondence between bits and RB Gs,assertion of a given bit is sufficient to notify a given UE 102 of itsresource allocation in a given sub-frame.

The base station 104 c may also create an array (also referred to as avector herein). Each indexed location in the array may identify adifferent asserted bit in the bitmap—in other words, the length of thearray may equal the number of asserted bits in the bitmap (correspondingto the number of allocated RBGs for that aggregation level). Thus, foran array index of 1, that identifies the first allocated bit in thebitmap, for an array index of 5, that identifies the fifth allocated bitin the bitmap, etc. This array is also included in the downlink controlmessage.

The base station 104 c may also list each UE identifier selected for thegiven aggregation level in a list in a field (also referred to herein asa C-RNTI field for illustrative purposes) of the common downlink controlmessage. The base station 104 c may take the value that identifies theorder in which each UE identifier is placed in the list and store thatvalue in the array elements whose indices correspond to the assertedbits for the given UE 102, which in turn identifies the RBG(s) allocatedfor that particular UE 102. While referencing order, this may correspondto the actual numbered order in which the UE 102 identifiers are placedin the list. For example, if the UE 102 h were assigned to two differentRBGs corresponding to the second and fourth asserted bits in the bitmap,then the base station 104 c places the UE 102 h in the list for thataggregation level's downlink control message, notes the location in thelist (e.g., second spot), and then places the value corresponding to thelocation value (here, 2 for the second spot) in the second and fourthindex locations in the array. The base station 104 c repeats this forall of the UEs 102 whose allocation is identified with the givenaggregation level, e.g. in their scheduled order. The base station 104 cthen multicasts the downlink control message to those UEs 102 listed inthe field of the downlink control message.

A similar result is achieved using the approach described above for theUEs 102 that are presently associated with other aggregation levels.Thus, a single multicast message may identify to multiple UEs 102 whichresources they have been allocated for one or more periods of time(e.g., for a subframe). In this manner, the number of data bits used forproviding downlink control messages may be noticeably reduced, therebyreducing the signaling overhead used for signaling resource allocation(and/or other parameters).

FIG. 2 is a block diagram of an exemplary wireless communication device200 according to embodiments of the present disclosure. The wirelesscommunication device 200 may be a base station having any one of manyconfigurations described above. For purposes of example, wirelesscommunication device 200 may be a base station 104 as discussed abovewith respect to FIG. 1. The base station 104 may include a processor202, a memory 204, a scheduler 208, a transceiver 210 (including a modem212 and RF unit 214), and an antenna 216. These elements may be indirect or indirect communication with each other, for example via one ormore buses.

The processor 202 may have various features as a specific-typeprocessor. For example, these may include a central processing unit(CPU), a digital signal processor (DSP), an application-specificintegrated circuit (ASIC), a controller, a field programmable gate array(FPGA) device, another hardware device, a firmware device, or anycombination thereof configured to perform the operations describedherein with reference to the base stations 104 introduced in FIG. 1above. The processor 202 may also be implemented as a combination ofcomputing devices, e.g., a combination of a DSP and a microprocessor, aplurality of microprocessors, one or more microprocessors in conjunctionwith a DSP core, or any other such configuration.

The memory 304 may include a cache memory (e.g., a cache memory of theprocessor 302), random access memory (RAM), magnetoresistive RAM (MRAM),read-only memory (ROM), programmable read-only memory (PROM), erasableprogrammable read only memory (EPROM), electrically erasableprogrammable read only memory (EEPROM), flash memory, solid state memorydevice, hard disk drives, other forms of volatile and non-volatilememory, or a combination of different types of memory. In someembodiments, the memory 204 may include a non-transitorycomputer-readable medium. The memory 204 may store instructions 206. Theinstructions 206 may include instructions that, when executed by theprocessor 202, cause the processor 202 to perform operations describedherein with reference to a base station 104 in connection withembodiments of the present disclosure. The terms “instructions” and“code” may include any type of computer-readable statement(s). Forexample, the terms “instructions” and “code” may refer to one or moreprograms, routines, sub-routines, functions, procedures, etc.“Instructions” and “code” may include a single computer-readablestatement or many computer-readable statements.

The scheduler 208 may be used for various aspects of the presentdisclosure. The scheduler 208 may include various hardware componentsand/or software components to assist in scheduling resources andinforming the scheduled UEs 102 of their assignments. For example, thescheduler 208 may be responsible for common and UE-specific resourceallocation assignments, such as the UE-specific resource allocationassignments according to embodiments of the present disclosure. Further,the scheduler 208 may determine what aggregation level any given UE 102is to be scheduled with. As part of this, the scheduler 208 maydetermine how many UEs 102 to multi-cast a given downlink controlmessage to at any given aggregation level.

The scheduler 208 may be responsible for generating and maintaining oneor more bitmaps, one for each aggregation level, that are used toidentify the resources (such as discussed with respect to FIG. 1 above).The scheduler 208 may be further responsible for generating one or morearrays, e.g. one for each aggregation level, that corresponds to thebitmap for that aggregation level as discussed above with respect toFIG. 1. Further, the scheduler 208 may be responsible for generating thelist in the field that identifies all of the UEs 102 that the particulardownlink control message is multicast to, including placing ordernumbers in the relevant array elements so that the UEs 102 may properlylocate their resource allocation information in the bitmap in thedownlink control message, such as discussed above with respect to FIG. 1and further with respect to additional figures below.

As shown, the transceiver 210 may include the modem subsystem 212 andthe radio frequency (RF) unit 214. The transceiver 210 can be configuredto communicate bi-directionally with other devices, such as UEs 102and/or other network elements. The modem subsystem 212 may be configuredto modulate and/or encode data according to a MCS, e.g., a LDPC codingscheme, a turbo coding scheme, a convolutional coding scheme, a polarcoding scheme, etc. The RF unit 214 may be configured to process (e.g.,perform analog to digital conversion or digital to analog conversion,etc.) modulated/encoded data from the modem subsystem 212 (on outboundtransmissions) or of transmissions originating from another source suchas a UE 102. Although shown as integrated together in transceiver 210,the modem subsystem 212 and the RF unit 214 may be separate devices thatare coupled together at the base station 104 to enable the base station104 to communicate with other devices.

The RF unit 214 may provide the modulated and/or processed data, e.g.data packets (or, more generally, data messages that may contain one ormore data packets and other information) such as the downlink controlmessages of the present disclosure, to the antenna 216 for transmissionto one or more other devices. This may include, for example,transmission of downlink control information in a control channel, suchas PDCCH, according to embodiments of the present disclosure. Theantenna 216 may further receive data messages transmitted from otherdevices and provide the received data messages for processing and/ordemodulation at the transceiver 210. Although FIG. 2 illustrates antenna216 as a single antenna, antenna 216 may include multiple antennas ofsimilar or different designs in order to sustain multiple transmissionlinks.

Turning now to FIG. 3, a block diagram is illustrated of an exemplarywireless communication device 300 according to embodiments of thepresent disclosure. The wireless communication device 300 may be a UE102 having any one of many configurations described above. For purposesof example, wireless communication device 300 may be a UE 102 asdiscussed above with respect to FIG. 1.

As shown, the UE 102 may include a processor 302, a memory 304, atransceiver 308 (including a modem 310 and RF unit 312), and an antenna314. In some embodiments, the UE 102 may include multiple transceivers308 (also referred to as multiple radios). These elements may be indirect or indirect communication with each other, for example via one ormore buses.

The processor 302 may include a CPU, a DSP, an ASIC, a controller, anFPGA device, another hardware device, a firmware device, or anycombination thereof configured to perform the operations describedherein with reference to UEs 102. In particular, the processor 302 maybe utilized in combination with the other components of the UE 102 toperform the various functions associated with embodiments of the presentdisclosure. The processor 302 may also be implemented as a combinationof computing devices, e.g., a combination of a DSP and a microprocessor,a plurality of microprocessors, one or more microprocessors inconjunction with a DSP core, or any other such configuration.

The memory 304 may include a cache memory (e.g., a cache memory of theprocessor 302), RAM, MRAM, ROM, PROM, EPROM, EEPROM, flash memory, solidstate memory device, hard disk drives, other forms of volatile andnon-volatile memory, or a combination of different types of memory. Inan embodiment, the memory 304 includes a non-transitorycomputer-readable medium. The memory 304 may store instructions 306. Theinstructions 306 may include instructions that, when executed by theprocessor 302, cause the processor 302 to perform the operationsdescribed herein with reference to the UEs 102 in connection withembodiments of the present disclosure. Instructions 306 may also bereferred to as code, which may be interpreted broadly to include anytype of computer-readable statement(s) as discussed above with respectto FIG. 2.

As shown, the transceiver 308 may include the modem subsystem 310 andthe radio frequency (RF) unit 312. The transceiver 308 can be configuredto communicate bi-directionally with other devices, such as basestations 104. The modem subsystem 310 may be configured to modulateand/or encode data from other aspects of the UE 102, such as processor302 and/or memory 304, according to an MCS, e.g., a LDPC coding scheme,a turbo coding scheme, a convolutional coding scheme, a polar codingscheme, etc. The RF unit 312 may be configured to process (e.g., performanalog to digital conversion or digital to analog conversion, etc.)modulated/encoded data from the modem subsystem 310 (on outboundtransmissions) or of transmissions originating from another source suchas a base station 104. Although shown as integrated together intransceiver 308, the modem subsystem 310 and the RF unit 312 may beseparate devices that are coupled together at the UE 102 to enable theUE 102 to communicate with other devices.

The RF unit 312 may provide the modulated and/or processed data, e.g.data packets (or, more generally, data messages that may contain one ormore data packets and other information), to the antenna 314 fortransmission to one or more other devices. This may include, forexample, transmission of information on assigned resources received andprocessed according to embodiments of the present disclosure. Theantenna 314 may further receive data messages transmitted from otherdevices and provide the received data messages for processing and/ordemodulation at the transceiver 308. Although FIG. 3 illustrates antenna314 as a single antenna, antenna 314 may include multiple antennas ofsimilar or different designs in order to sustain multiple transmissionlinks.

For example, according to embodiments of the present disclosure, thetransceiver 308 may listen for downlink control messages (e.g., one ormore DCIs) during PDCCH portions of subframes. The transceiver 308 maylisten for the downlink control messages during multiple different CCEindexes associated with different aggregation levels. Information aboutmultiple aggregation levels may be obtained from those DCIs in CCEs thatdid not allocate resources for the listening UE 102, such as will bediscussed in further detail below with respect to bit reduction.

When the antenna 314 receives a downlink control message, thetransceiver 308 may attempt to decode it with the coding rate of thegiven aggregation level for the given CCE index. In embodiments wherethe bitmap sizes are the same for each aggregation level, the processor302 may discard information from the downlink control message where theUE 102 is not listed in the C-RNTI field (or, more generally, the UEidentifier field). In embodiments where there is bit reduction, so thatthe bitmap sizes are not the same for each aggregation level, theprocessor 302 may store bitmaps for higher aggregation levels forsubsequent use, e.g. in memory 304.

Either way, according to embodiments of the present disclosure, when theantenna 314 receives a downlink control message that has been multicastto the UE 102 from the base station 104, the transceiver 308 process thereceived data so that the processor 302 may access the UE identifierfield to locate its particular UE identifier (e.g., C-RNTI or somereduced replacement for that to further optimize bit usage in thedownlink message) in the list in that field. For example, the processor302 may access the UE identifier assigned to the UE 102 and compare itagainst those provided in the list in the UE identifier field of thedownlink control message. Upon locating a matching UE identifier in thelist, the processor 302 may at the same time determine the order inwhich the matching UE identifier was located in the list (e.g., first,second, third, etc.).

The processor 302 also accesses the array included in the downlinkcontrol message. As noted above, the array has a length that is equal tothe number of asserted bits in the bitmap included with the downlinkcontrol message. The processor 302 takes the array and searches throughit to find each index location in which the order value obtained fromthe list has been placed. Thus, if the UE identifier for the UE 102 wasfound in the second slot in the list, then the processor 302 wouldsearch for the order value 2 in the array. At each array element that amatch is located (in this example, the value 2), the processor 302 mayidentify the array index value for that array element.

The processor 302 also accesses the bitmap included in the downlinkcontrol message. With the array index value(s) obtained from the array,the processor 302 passes through the bitmap to locate the assertedbit(s) corresponding to the identified array index value(s). Forexample, if the processor 302 located the value 2 at two separate indexlocations in the array, such as the fourth and sixth index locations inthe array, then the processor 302 can work sequentially through thebitmap to identify the fourth and sixth asserted bits—in other words,when the processor 302 finds the first asserted bit (e.g., “1”), that isthe first asserted bit, then the second asserted bit, etc. until itlocates the fourth asserted bit. Thus, the array index values maycorrespond to bits that are much further into the bitmap than the valueof the array index.

The processor 302, upon locating the asserted bits in the bitmap thathave been identified based on the UE identifier list and the array indexvalues, the processor 302 may identify the resource elements (e.g.,RBGs) that are represented by the particular locations in the bitmap.With this information, the UE 102 is then ready to communicate with theallocated resources at the appropriate time and frequencies.

In an embodiment, the base station 104 may communicate the same size ofbitmap at each aggregation level. In this situation, the UE 102 maytreat each downlink control message at each aggregation level separately(e.g., ignoring those that are not at its aggregation level whether bydesign or due to the fact that the message was coded at a rate the UE102 is not currently capable of handling). In another embodiment, bitreduction (also referred to as a super-optimization for bitusage/overhead reduction) may be in use. This occurs where, for eachlower aggregation level, the bitmap has been reduced by removing thosebits that were asserted for the higher aggregation level(s). Thus, at anaggregation level 4, those bits that were asserted to identify resourceallocations for those UEs 102 presently at aggregation level 8 may beremoved from the bitmap that is sent with the resource allocations forUEs 102 presently at aggregation level 4. Further, at an aggregationlevel 2, those bits asserted for aggregation level 8 remain removed andnow those bits asserted for aggregation level 4 are removed. Thus, foreach lower aggregation level, the size of the bitmap may continue todecrease, reducing the number of bits and therefore signaling overheadfor a given multicast.

Where bit reduction is in use (and may be signaled to the UE 102beforehand that it is), the UE 102 may also pay attention to any higherlevel aggregation level multicasts. Thus, if a UE 102 is at aggregationlevel 4, it will listen to both the aggregation level 8 and aggregationlevel 4 multicasts. This is possible since, in some embodiments of thepresent disclosure, the downlink control messages at any of theaggregation levels may be transmitted “clear” (e.g., not scrambledaccording to any values that are inaccessible to some UEs in anenvironment) so that any of the UEs 102 in a multicast (or others thatare waiting for a lower-level multicast) can receive and decode them.

Once the UE 102 that is at aggregation level 4 receives the aggregationlevel 8 downlink control message, the UE 102 may retrieve the bitmap(referred to for this example as the AL-8 bitmap) and at leasttemporarily store it in the memory 304. The AL-8 bitmap, being in thisexample the highest level aggregation level for the system, lists thefull range of bits representing the full range of allocable RBGs (orresource elements generally). When the UE 102 receives the aggregationlevel 4 downlink control message, the UE 102 may retrieve the bitmap(referred to for this example as the AL-4 bitmap) from the message. TheUE 102 may access the AL-8 bitmap it is storing in memory 304 andcompare the AL-4 bitmap against the AL-8 bitmap. This comparison may beperformed after the UE 102 has already identified the relevant bitmaplocations in the AL-4 bitmap that represent the resources allocated tothe UE 102 (as obtained from the UE identifier list and the array asdiscussed above).

With this information, the processor 302 may compare the AL-4 bitmapagainst the AL-8 bitmap in order to identify which bits were removed forthe AL-4 bitmap's downlink control message. With any removed bitsidentified, the processor 302 may then reconstruct the full bitmap withthe location of the asserted bits for the UE 102 maintained. In thismanner, the UE 102 may then identify its allocated resources for atleast the assigned subframe.

FIG. 4A is a block diagram of an exemplary downlink frame structure 400according to embodiments of the present disclosure. It provides anillustrative example of how a downlink subframe may be organized. Aframe 401 may have a duration t (e.g., 10 ms) and may be divided intosome number of equally sized subframes (e.g., 10).

Each subframe may include consecutive time slots, such as two. Aresource grid may be used to represent two time slots, each time slotincluding a resource block (RB). Further, multiple RBs (e.g.,representing multiple groupings of subcarriers) may be grouped togetheras the RBGs mentioned above with respect to FIG. 1. The resource grid(illustrated in FIG. 4A with respect to a particular RB) may be dividedinto multiple resource elements. For a cyclic prefix (e.g., according toLTE), a resource block may contain 12 consecutive subcarriers in thefrequency domain and 7 consecutive OFDM symbols in the time domain, fora total of 84 resource elements. For an extended cyclic prefix, an RBmay contain 12 consecutive subcarriers in the frequency domain and 6consecutive OFDM symbols in the time domain, for a total of 72 resourceelements.

Some of the resource elements may include DL reference signals (e.g.,DL-RS). The DL-RS may include Cell-specific RS (CRS) (also sometimescalled common RS) and UE-specific RS (UE-RS), to name some examples.UE-RS may be transmitted only on the resource blocks upon which thecorresponding physical DL shared channel (PDSCH) is mapped. The numberof bits carried by each resource element depends on the modulationscheme. Thus, the more resource blocks that a UE 102 receives and thehigher the modulation scheme, the higher the data rate for the UE 102.

In the illustrated example, several symbols in a subframe may bereserved for use as the PDCCH, and may include a normal cyclic prefix.With this limited size for the PDCCH, the total number of downlinkcontrol messages that may be transmitted per a given subframe may belimited by the aggregation level selected for any given downlink controlmessage (e.g., a higher aggregation level increases the size of thedownlink control message, thereby reducing the number of downlinkcontrol messages that can be transmitted in that subframe's PDCCH).

An example of a downlink control message is illustrated in FIG. 4B,which provides a block diagram of an exemplary downlink control messagestructure 410 according to embodiments of the present disclosure. Asillustrated in FIG. 4A, the downlink control message structure 410 mayinclude a bitmap 412, an array 414, and a field 416 (also referred to asa list 416, or a UE identifier field or list 416). Other data fields maybe included but are not presently illustrated so as not to obscureembodiments of the present disclosure

A relationship between the bitmap 412, the array 414, and the list 416is illustrated in FIG. 4C, which is a block diagram of an exemplarydownlink control message structure relationship according to embodimentsof the present disclosure.

As illustrated in FIG. 4C, the bitmap 412 may include a plurality of bitvalues 420. The series of bit values illustrated in FIG. 4C, andelsewhere (e.g., “0 0 0 1 0 . . . ”) is exemplary only. Any given bitmap412 may have any permutation of 0 and 1. In the illustrated embodiment,“1” is an asserted bit and corresponds to a resource that has beenassigned (and that the bit is mapped to at both the base station 104 andthe UE 102). Further, the size of the bitmap 412 (as well as the size ofthe array 414 and the list 416) is exemplary as well—any number ofresource elements (e.g., RBGs) may be available and represented viabitmap.

Further, any number of resources may be allocated per aggregation level,and since the array 414's size is based upon the number of bits assertedin the bitmap 412, the size of the array 414 is also variable. In FIG.4C, the array 414 is illustrated to show that each array element 422 mayhave its own index value on top of whatever order value is stored in thearray element according to embodiments of the present disclosure(indexed starting at 1 in this example, though any other value may beused as well). Further, since the number of UEs 102 that may be assignedresources at a given aggregation level is variable as well, the size ofthe list 416 may vary to accommodate whatever number of UEs 102 areassigned at that level at that time (since the aggregation level atwhich a UE 102 is placed may vary as conditions and/or the position ofthe UE 102 changes).

An example may illustrate the relationship between the bitmap 412, thearray 414, and the UE identifier list 416. A particular UE 102 having UEidentifier RNTI-2 may be scheduled to have resources allocated to it ata given aggregation level. This is reflected in UE identifier list 416,where RNTI-1, RNTI-2, RNTI-3, and RNTI-4 are all listed as beingallocated resources at the same aggregation level. Looking at RNTI-2specifically, it is listed in order number 2 (indexed from 0 in thisexample, while in other examples numbering may begin instead from 1). Asa result, when looking at the array 414, the order number 2 is searchedfor throughout the length of the array 414.

In this example, wherever the order number 2 is stored, the index valuefor that array element is used to map to the bitmap 412. Thus, when abase station 104 creates the array 414 and the values in it for a givenaggregation level, it stores the appropriate values corresponding to theorder values in array elements whose index values map to the RBG(s)allocated for those respective UEs 102 in that aggregation level.Similarly, when a UE 102 is determining its allocated resources, itlooks for the order number to identify locations in the bitmap. Althoughthe order values are illustrated in FIG. 4C as being in a repeatingpattern, the order values may be placed in any order that causes theindex values for those array elements to point to the correct locations424/426 in the bitmap 412.

For example, searching for the order number 2 in the array elements 422,in FIG. 4C's example the array index values 3 and 7 correspond to thearray elements 422 that store the matching value 2. This means that theRBGs allocated to the UE 102 having the identifier RNTI-2 are identifiedby the third and seventh asserted bits in the bitmap 412. This is shownwith the bits 424 and 426 in bitmap 412—the bit 424 corresponds to thethird time that “1” is asserted in this particular bitmap, and the bit426 corresponds to the seventh time that “1” is asserted in thisparticular bitmap.

FIG. 5A is a flowchart illustrating bitmap structure per aggregationlevel according to embodiments of the present disclosure. The bitmapstructure in FIG. 5A corresponds to a first embodiment where the bitmap412 length for each aggregation level corresponds to the number ofavailable resources (in this example, RBGs) for scheduling/allocation.The particular bits 420, both the total amount and their order ofasserted/not asserted, as illustrated is exemplary only.

As illustrated, as the highest aggregation level (here, AL-8, oraggregation level 8), the number of bits 420 corresponds to the numberof RBGs available for allocation. Thus, the bitmap 412 length equals thenumber of RBGs overall available for allocation. Further, the length ofthe UE identifier field may be of ceiling (log₂(1+N_(UEX))) for each ofthe RBGs actually used in the given aggregation level (in this example,AL-8). The length of the UE identifier list 416 corresponds to thelength for each UE identifier*the total number of UEs allocated for thatlevel. If the actual C-RNTI were used for each UE 102 assigned ataggregation level 8, then the length would increase accordingly to thenumber of UEs*the length of each C-RNTI.

The length of the overall downlink control message for aggregation level8 that includes the bitmap 412 would also include the length of thearray 414, which corresponds to the number of bits asserted for thataggregation level.

Following a similar pattern for the other aggregation levels illustratedin FIG. 5A, the downlink control messages at aggregation level 4 wouldinclude the same length bitmap 412 as was included for aggregation level8 (e.g., no further optimization is done to the bitmap 412 foraggregation level 4), and similarly for the bitmaps 412 at aggregationlevels 2 and 1. The length of the downlink control messages at eachlevel, therefore, becomes a function of the number of UEs 102 whoseresource allocations are notified at those levels.

FIG. 5B is a flowchart illustrating bitmap structure per aggregationlevel according to embodiments of the present disclosure. In thisalternative embodiment to that illustrated in FIG. 5A, further bitoptimization (in other words, further reducing the number of bits in agiven downlink control message) may be obtained, also referred to hereinas bit reduction (referring to reducing the number of bits used for agiven downlink control message) by further manipulation of the bitmaps412.

As illustrated, the length of the bitmap 412 at the highest aggregationlevel, here AL-8, remains the same size as the bitmap 412 illustrated inFIG. 5A (a bit for each RBG available for allocation). This may beoptimized at lower aggregation levels. This is illustrated at the nextlevel below AL-8, here AL-4. At AL-4, the bitmap 412 is modified beforeinclusion in a downlink control message so that those bits that werealready asserted are removed from the bitmap 412. After removing thosebits that were asserted at the higher aggregation level, the resultingbitmap 412.a is smaller by the number of bits asserted at the higherlevel (in this example, 8 fewer bits). Thus, the downlink controlmessage for UEs 102 being allocated in aggregation level 4 is reduced bythat number of bits, a further optimization.

The example continues at the next lower aggregation level, here AL-2. Ataggregation level 2, the base station 104 further removes from thebitmap 412 both those bits that were asserted for aggregation level 8and for aggregation level 4 (or, alternatively, just from bitmap 412.a).After removing those bits that were asserted at the higher aggregationlevels (both AL-8 and AL-4 here), the resulting bitmap 412.b is smallerby the number of bits asserted at the higher level (in this example, 4fewer bits than bitmap 412.a, and therefore 12 fewer bits than bitmap412 in total). Thus, the downlink control message for UEs 102 beingallocated at aggregation level 2 is reduced by that number of bits, yeta further optimization.

Continuing the example at the next lower aggregation level, here AL-2,the base station 104 further removes from the bitmap 412 those bits thathave been asserted at all of the higher aggregation levels (AL-8, AL-4,and AL-2). After removing those bits that were asserted at higherlevels, the resulting bitmap 412.c is yet smaller by those number ofbits that were asserted at all of the higher levels. In this example,bitmap 412.c is 6 bits less in length than the bitmap 412.b, andtherefore 18 fewer bits than bitmap 412 in total. This results in afurther optimization.

With this alternative embodiment, as noted above, the UEs 102 that areassigned to lower aggregation levels listen to the downlink controlmessages of the higher aggregation levels in order to obtain a fullpicture of the full bitmap 412 in order dynamically obtain theirresource allocations according to the other embodiments of the presentdisclosure (e.g., by mapping from the UE identifier list 416 to thearray 414, and from there to the bitmap 412 recovered from the shortenedbitmap at the given lower aggregation level).

Turning now to FIG. 6, a flowchart is illustrated of an exemplary method600 for wireless communication in accordance with various aspects of thepresent disclosure. In particular, the method 600 illustrates thecreation and transmission of downlink control messages based onscheduled resources according to embodiments of the present disclosure.Method 600 may be implemented by a base station 104 (any number of basestations 104). It is understood that additional steps can be providedbefore, during, and after the steps of method 600, and that some of thesteps described can be replaced or eliminated from the method 600.

At block 602, the base station 104 starts with the first aggregationlevel, which in embodiments of the present disclosure is the highestaggregation level. For example, the highest level may be aggregationlevel 8 as discussed above.

At block 604, the base station 104 schedules a resource (or multiple)for a UE 102. This UE 102 is one that has been scheduled for the currentaggregation level, for example based on one or more channel qualitymeasures and/or preferences. For example, the resource may be a resourceblock group that is being allocated for the UE 102.

At block 606, the base station 104 asserts a bit in a bitmap 412 thatcorresponds to the resource allocated at block 604. The bitmap has alength equal to the total number of resources available for scheduling,with a different bit corresponding to a different RBG. The granularitymay be, for example, per RBG (e.g., X number of RBGs available forscheduling in a bandwidth of Y of the system). Assertion of a bit, e.g.to a “1” instead of a “0”, identifies that the RBG associated with thatparticular bit has been allocated at block 604.

At block 608, the base station 104 places a UE identifier in a list 416in a field that will be included in the downlink control message topotentially multiple UEs 102. In an embodiment, the UE identifier may bea reduced form of a specific identifier, such as the C-RNTI, for exampleas obtained from log₂(1+N*UE_(X)) for the given order of the schedulingfor the UE 102 in the current aggregation level. In another embodiment,the UE identifier may be the C-RNTI that is included in the list.

At block 610, the base station 104 notes the order of placement of theUE identifier into the list. This is so that the order number may bestored at one or more locations in an array as discussed with respect toblock 614, according to aspects of the present disclosure. Further, thebase station 104 notes the RBG allocations and the order in which thedifferent UEs 102 are allocated those RBGs by the asserted bits in thebitmap 412.

At decision block 612, if there are more UEs 102 to schedule at thecurrent aggregation level, then the method 600 returns to block 604 andproceeds as discussed above. This description is for ease ofillustration; although the scheduling is described as occurringsequentially, the scheduling may occur concurrently for multiple UEs 102at a given aggregation level, as well as the modification of the bitmapand/or placements in the list.

If there are no more UEs 102 to schedule at the current aggregationlevel, then the method 600 proceeds to block 614.

At block 614, the base station 104 generates an array 414 whose lengthequals the total number of bits asserted in the bitmap 412. Allowing thearray 414 to be dynamically sized per aggregation level per round ofscheduling provides an optimization in the overall size of the downlinkcontrol messaging.

At block 616, the base station 104 places the order numbers for thedifferent UE identifiers placed in the list 416 at block 610 intodifferent array elements 422 of the array 414 according to the order ofassignment in the bitmap 412. Thus, if a UE identifier was placed in thesecond place in the list 416, the base station 104 makes note of thisuses the numerical value of 2 to represent the UE 102 in the array 414(thus achieving a dynamic mapping for this downlink control signal to afurther reduced value representing the UE 102, resulting in reduced bitsize). Further, based on the noted order of allocation in the bitmap,the base station 104 places the numerical value of 2 at index locationsin the array 414 that correspond to the bits representing RBGs allocatedto the particular UE 102. For example, the i^(th) index value in thearray 414 identifies the i^(th) asserted bit (not overall bits) in thebitmap 412.

At decision block 618, if there are more aggregation levels (e.g., loweraggregation levels from the current aggregation level), then the method600 proceeds to decision block 620.

At decision block 620, if bit reduction is not being utilized for loweraggregation levels, then the method 600 proceeds to block 622, where thebase station 104 transitions to the next aggregation level (e.g., from 8to 4, 4 to 2, 2 to 1).

If it is instead determined at decision block 620 that bit reduction isbeing utilized, then the method 600 proceeds to block 624, where thebase station 104 transitions to the next aggregation level.

At block 626, the base station 104 proceeds through the actionsdescribed above with respect to blocks 602 through 616, includingscheduling, asserting bits in the bitmap for the current aggregationlevel, populating the list, and generating/finalizing the array for theaggregation level for all the UEs 102 scheduled for that aggregationlevel.

At block 628, the base station 104 reduces the size of the bitmap forthe current aggregation level based on the bits asserted for the higheraggregation level(s). For example, at aggregation level 4, the basestation 104 removes those bits from the bitmap 412 that were assertedfor the bitmap 412 at aggregation level 8. At aggregation level 2, thebase station removes those bits from the bitmap 412 that were assertedfor the bitmap 412 at aggregation level 8 and those bits that wereasserted at aggregation level 4, etc.

At decision block 630, if there are any more lower aggregation levels,then the method 600 returns to block 624 and proceeds as describedabove. If there are not any more lower aggregation levels, then themethod 600 proceeds to block 632, where the downlink control messagesfor the different aggregation levels are transmitted per theiraggregation level (e.g., a CCE index assigned to a given aggregationlevel). Although described here as transmissions waiting until allaggregation levels have been proceeds for a given subframe, transmissionmay alternatively occur as each aggregation level's processing iscompleted at the base station 104. As noted above, various aspects mayoccur in a different order than that discussed here, for example withrespect to blocks 606-616.

Returning to decision block 618, if there are not any more aggregationlevels (lower levels) and bit reduction is not being implemented (e.g.,the FIG. 5A embodiment is being implemented), then the method 600proceeds to block 632 as described above.

Turning now to FIG. 7, a flowchart is illustrated of an exemplary method700 for wireless communication in accordance with various aspects of thepresent disclosure. In particular, the method 700 illustrates thereception and processing of downlink control messages based on scheduledresources according to embodiments of the present disclosure. Method 700may be implemented by a UE 102 (any number of UEs 102). It is understoodthat additional steps can be provided before, during, and after thesteps of method 700, and that some of the steps described can bereplaced or eliminated from the method 700.

At block 702, the UE 102 listens for a downlink control message at oneor more CCE indexes assigned to one or more aggregation levels. Forexample, the UE 102 may listen to those CCE index(es) assigned toaggregation level 8 as well as level 4 (e.g., where the UE 102′sallocation is included in a downlink control message at aggregationlevel 4).

At decision block 704, if the UE 102 has not located a UE identifierassociated with it (e.g., C-RNTI or a reduced version of C-RNTI), thenthe method 700 returns to block 702 to listen for the next downlinkcontrol message at the next aggregation level (e.g., at a subsequent CCEindex).

If, at decision block 704, the UE 102 has received a downlink controlmessage in the current aggregation level that identifies the UE 102 withits identifier, then the method 700 proceeds to block 706.

At block 706, the UE 102 decodes the received downlink control messagebased on the coding rate for the aggregation level.

At block 708, the UE 102 accesses the bitmap 412 from the decodeddownlink control message from block 706.

At decision block 710, if bit reduction is being utilized for loweraggregation levels, then the method 700 proceeds to block 712.

At block 712, the UE 102 decodes the bitmap(s) 412 from the higheraggregation level downlink control messages. For example, whenever theUE 102 receives a downlink control message at block 702 that is not atthe proper aggregation level (e.g., is at a higher aggregation levelsince the higher aggregation levels are transmitted in sequence beforethe lower levels), it may store it at least temporarily or at leastextract the bitmap from each level above the current level forretention. With these higher-level bitmaps 412, the UE 102 repopulates afull bitmap for the current aggregation level.

For example, if the current aggregation level is AL-4, as illustrated inFIG. 5B for bit reduction, the bitmap 412.a is reduced by removal (atthe base station 104) of the bits that were asserted for AL-8. Thus,upon receiving the reduced bitmap 412.a, the UE 102 accesses theoriginal bitmap 412 from AL-8 to re-integrate those asserted bits forAL-8 that had been removed, so that the UE 102 is able to locate theproper order of asserted bits when determining its resource allocation.

At block 714, the UE 102 accesses the UE identifier field in thedownlink control message for the current aggregation level. From thisfield the UE 102 obtains the UE identifier list 416 as identified inFIGS. 4B and 4C above.

Returning to decision block 710, if bit reduction is not being utilizedthen the method 700 proceeds to block 714 as described above.

Whether bit reduction is used or not, from block 714 the method 700proceeds to block 716. At block 716, the UE 102 locates its UEidentifier in the UE identifier list 416 and makes note of the ordernumber (also referred to as an order value) in which the UE identifierwas placed in the list 416. For example, if the UE 102′s identifier wassecond in the list, then the UE 102 would set an order number of 2. Thisis used to dynamically map to the proper location in an array 414.

At block 718, the UE 102 accesses the array 414 from the downlinkcontrol message for the current aggregation level.

At block 720, the UE 102 searches the array 414 to find array elementsthat are storing a value that matches the order number obtained for theUE identifier from block 716. This provides a dynamic mapping from theUE identifier to a shorter value so that the downlink control messagemay be reduced in size.

At block 722, the UE 102 identifies the index values for each arrayelement found to be storing a matching value to the order numberobtained for the UE identifier of the UE 102. There may be one or moreindex values, corresponding to one or more resources being allocated tothe UE 102.

At block 724, the UE 102 takes the index values identified from block722 and locates the asserted bits in the bitmap 412 that represent theresources (e.g., RBGs) allocated to the UE 102. Thus, the numericalvalue of the index value represents how many asserted bits in from thestart of the bitmap 412 to traverse to arrive at the asserted bit whichrepresents the allocated resource corresponding to that index value(e.g., the i^(th) index value in the array 414 identifies the i^(th)asserted bit in the bitmap 412 for the resource). This may repeat for asmany index values that are identified from block 720. As noted above,various aspects may occur in a different order than that discussed here,for example with respect to blocks 714-724.

At block 726, the UE 102 identifies the allocated resources (e.g. RBGs)that correspond to the asserted bit (or bits) located at block 724.

Information and signals may be represented using any of a variety ofdifferent technologies and techniques. For example, data, instructions,commands, information, signals, bits, symbols, and chips that may bereferenced throughout the above description may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, or any combination thereof.

The various illustrative blocks and modules described in connection withthe disclosure herein may be implemented or performed with ageneral-purpose processor, a DSP, an ASIC, an FPGA or other programmablelogic device, discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed herein. A general-purpose processor may be a microprocessor,but in the alternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices (e.g., a combinationof a DSP and a microprocessor, multiple microprocessors, one or moremicroprocessors in conjunction with a DSP core, or any other suchconfiguration).

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on acomputer-readable medium. Other examples and implementations are withinthe scope of the disclosure and appended claims. For example, due to thenature of software, functions described above can be implemented usingsoftware executed by a processor, hardware, firmware, hardwiring, orcombinations of any of these. Features implementing functions may alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations.

Also, as used herein, including in the claims, “or” as used in a list ofitems (for example, a list of items prefaced by a phrase such as “atleast one of” or “one or more of”) indicates an inclusive list suchthat, for example, a list of [at least one of A, B, or C] means A or Bor C or AB or AC or BC or ABC (i.e., A and B and C). It is alsocontemplated that the features, components, actions, and/or stepsdescribed with respect to one embodiment may be structured in differentorder than as presented herein and/or combined with the features,components, actions, and/or steps described with respect to otherembodiments of the present disclosure.

Embodiments of the present disclosure include a computer-readable mediumhaving program code recorded thereon, the program code comprising codefor causing an access point to generate a first downlink control messagecomprising a first set of resource allocations to a first plurality ofwireless communications devices, the first plurality of wirelesscommunications devices being assigned to a first aggregation level. Theprogram code further comprises code for causing the access point togenerate a second downlink control message comprising a second set ofresource allocations to a second plurality of wireless communicationsdevices, the second plurality of wireless communications devices beingassigned to a second aggregation level that is different from the firstaggregation level. The program code further comprises code for causingthe access point to transmit the first downlink control message to thefirst plurality of wireless communications devices and the seconddownlink control message to the second plurality of wirelesscommunications devices.

The computer-readable medium further includes code for causing theaccess point to include a first bitmap having a first plurality of bitsin the first downlink control message, wherein each bit from among thefirst plurality of bits corresponds to a different resource and anasserted bit in the first bitmap corresponds to a resource allocationfrom among the first set of resource allocations, and code for causingthe access point to include a second bitmap having a second plurality ofbits in the second downlink control message, wherein each bit from amongthe second plurality of bits corresponds to a different resource and anasserted bit in the second bitmap corresponds to a resource allocationfrom among the second set of resource allocations. The computer-readablemedium further includes code for causing the access point to include afirst array having a first total number of array elements in the firstdownlink control message, the first total number of array elementsequaling a total number of assigned bits from among the first pluralityof bits in the first bitmap, each array element identifying a wirelesscommunications device from the first plurality of wirelesscommunications devices, and code for causing the access point to includea second array having a second total number of array elements in thesecond downlink control message, the second total number of arrayelements equaling a total number of assigned bits from among the secondplurality of bits in the second bitmap, each array element identifying awireless communications device from the second plurality of wirelesscommunications devices. The computer-readable medium further includescode for causing the access point to include a first field in the firstdownlink control message, the first field comprising a first identifierin a list of identifiers for the first plurality of wirelesscommunications devices, and code for causing the access point to includea second field in the second downlink control message, the second fieldcomprising a second identifier in a list of identifiers for the secondplurality of wireless communications devices. The computer-readablemedium further includes code for causing the access point to place thefirst identifier in a position in the list of the first field that has afirst order value, wherein each position in the list of identifiers inthe first field corresponds to a different order value, and code forcausing the access point to place the first order value in at least onearray element of the first array identifying the wireless communicationsdevice from the first plurality of wireless communications devices thatidentifies at least one assigned bit in the first bitmap thatcorresponds to at least one resource allocation from among the first setof resource allocations. The computer-readable medium further includeswherein an amount of the first plurality of bits equals an amount of thesecond plurality of bits. The computer-readable medium further includeswherein an amount of the first plurality of bits is greater than anamount of the second plurality of bits. The computer-readable mediumfurther includes wherein the first plurality of bits comprises a subsetof assigned bits to at least one wireless communications device fromamong the first plurality of wireless communications devices, furthercomprising code for causing the access point to reduce a length of thesecond bitmap by removing bit positions from the second bitmap thatcorrespond to the first set of resource allocations represented by thesubset of assigned bits in the first bitmap. The computer-readablemedium further includes wherein the second plurality of wirelesscommunications devices determine the second set of resource allocationsby reconstructing the second bitmap to have a same number of bits as thefirst bitmap after obtaining the subset of assigned bits from the firstbitmap. The computer-readable medium further includes code for causingthe access point to assign the first downlink control message to a firstindex in a downlink control channel, code for causing the access pointto assign the second downlink control message to a second index in thedownlink control channel, the second index being higher than the firstindex, and code for causing the access point to transmit the firstdownlink control message before the second downlink control messagebased on the assigned first and second indexes.

Embodiments of the present disclosure further include acomputer-readable medium having program code recorded thereon, theprogram code comprising code for causing a wireless communicationsdevice to receive a multicast downlink control message to a plurality ofwireless communications devices including the wireless communicationsdevice according to an aggregation level from an access point. Theprogram code further comprises code for causing the wirelesscommunications device to extract a resource allocation by the accesspoint for the wireless communications device from among a plurality ofresource allocations to the plurality of wireless communications devicesin the multicast downlink control message. The program code furthercomprises wherein the aggregation level is one from among a plurality ofdifferent aggregation levels.

The computer-readable medium further includes code for causing thewireless communications device to access a bitmap having a plurality ofbits, wherein each bit from among the plurality of bits corresponds to adifferent resource and an asserted bit in a subset of asserted bits fromthe plurality of bits corresponds to the resource allocation for thewireless communications device. The computer-readable medium furtherincludes code for causing the wireless communications device to access afield in the multicast downlink control message, code for causing thewireless communications device to locate an identifier associated withthe wireless communications device from among a list of identifiers, andcode for causing the wireless communications device to determine anorder value associated with the located identifier. Thecomputer-readable medium further includes code for causing the wirelesscommunications device to access an array comprising a plurality of arrayelements, each array element being identified in the array by an indexvalue, code for causing the wireless communications device to search forthe determined order value in the array, and code for causing thewireless communications device to identify at least one index valuecorresponding to at least one array element in which the determinedorder value is located. The computer-readable medium further includescode for causing the wireless communications device to determine whichat least one asserted bit from among the subset of asserted bitscorresponds to the at least one identified index value, and code forcausing the wireless communications device to determine the resourceallocation identified by the at least on asserted bit located by the atleast one identified index value. The computer-readable medium furtherincludes wherein the multicast downlink control message comprises asecond multicast downlink control message, the aggregation levelcomprises a second aggregation level, and the plurality of wirelesscommunications device comprises a second plurality of wirelesscommunications devices. The computer-readable medium further includescode for causing the wireless communications device to receive a firstmulticast downlink control message from the access point according to afirst aggregation level, and code for causing the wirelesscommunications device to access a first bitmap having a first pluralityof bits from the first multicast downlink control message, the bitmapaccessed from the second multicast downlink control message comprising asecond bitmap having a second plurality of bits. The computer-readablemedium further includes wherein each bit from among the first pluralityof bits corresponds to a different resource that provides resourceallocations to a first plurality of wireless communications devicesother than the wireless communications device. The computer-readablemedium further includes wherein an amount of the first plurality of bitsequals an amount of the second plurality of bits. The computer-readablemedium further includes wherein an amount of the first plurality of bitsis greater than an amount of the second plurality of bits, the length ofthe second plurality of bits having been reduced by removal of bitpositions in the second plurality of bits that correspond to differentresources represented by a subset of assigned bits in the first bitmap.The computer-readable medium further includes code for causing thewireless communications device to identify the subset of assigned bitsin the first bitmap, code for causing the wireless communications deviceto reconstruct the second bitmap to have a same number of bits as thefirst bitmap based on the identified subset of assigned bits in thefirst bitmap, and code for causing the wireless communications device todetermine the resource allocation based on the reconstructed secondbitmap. The computer-readable medium further includes code for causingthe wireless communications device to listen for the first multicastdownlink control message at an assigned first index in a downlinkcontrol channel, and code for causing the wireless communications deviceto listen for the second multicast downlink control message at anassigned second index in the downlink control channel, the second indexbeing after the first index.

Embodiments of the present disclosure further include an apparatuscomprising means for generating a first downlink control messagecomprising a first set of resource allocations to a first plurality ofwireless communications devices, the first plurality of wirelesscommunications devices being assigned to a first aggregation level. Theapparatus further comprises means for generating a second downlinkcontrol message comprising a second set of resource allocations to asecond plurality of wireless communications devices, the secondplurality of wireless communications devices being assigned to a secondaggregation level that is different from the first aggregation level.The apparatus further comprises means for transmitting the firstdownlink control message to the first plurality of wirelesscommunications devices and the second downlink control message to thesecond plurality of wireless communications devices.

The apparatus further includes means for including a first bitmap havinga first plurality of bits in the first downlink control message, whereineach bit from among the first plurality of bits corresponds to adifferent resource and an asserted bit in the first bitmap correspondsto a resource allocation from among the first set of resourceallocations, and means for including a second bitmap having a secondplurality of bits in the second downlink control message, wherein eachbit from among the second plurality of bits corresponds to a differentresource and an asserted bit in the second bitmap corresponds to aresource allocation from among the second set of resource allocations.The apparatus further includes means for including a first array havinga first total number of array elements in the first downlink controlmessage, the first total number of array elements equaling a totalnumber of assigned bits from among the first plurality of bits in thefirst bitmap, each array element identifying a wireless communicationsdevice from the first plurality of wireless communications devices, andmeans for including a second array having a second total number of arrayelements in the second downlink control message, the second total numberof array elements equaling a total number of assigned bits from amongthe second plurality of bits in the second bitmap, each array elementidentifying a wireless communications device from the second pluralityof wireless communications devices. The apparatus further includes meansfor including a first field in the first downlink control message, thefirst field comprising a first identifier in a list of identifiers forthe first plurality of wireless communications devices, and means forincluding a second field in the second downlink control message, thesecond field comprising a second identifier in a list of identifiers forthe second plurality of wireless communications devices. The apparatusfurther includes means for placing the first identifier in a position inthe list of the first field that has a first order value, wherein eachposition in the list of identifiers in the first field corresponds to adifferent order value, and means for placing the first order value in atleast one array element of the first array identifying the wirelesscommunications device from the first plurality of wirelesscommunications devices that identifies at least one assigned bit in thefirst bitmap that corresponds to at least one resource allocation fromamong the first set of resource allocations. The apparatus furtherincludes wherein an amount of the first plurality of bits equals anamount of the second plurality of bits. The apparatus further includeswherein an amount of the first plurality of bits is greater than anamount of the second plurality of bits. The apparatus further includeswherein the first plurality of bits comprises a subset of assigned bitsto at least one wireless communications device from among the firstplurality of wireless communications devices. The apparatus furtherincludes means for reducing a length of the second bitmap by removingbit positions from the second bitmap that correspond to the first set ofresource allocations represented by the subset of assigned bits in thefirst bitmap, wherein the second plurality of wireless communicationsdevices determine the second set of resource allocations byreconstructing the second bitmap to have a same number of bits as thefirst bitmap after obtaining the subset of assigned bits from the firstbitmap. The apparatus further includes means for assigning the firstdownlink control message to a first index in a downlink control channel,means for assigning the second downlink control message to a secondindex in the downlink control channel, the second index being higherthan the first index, and means for transmitting the first downlinkcontrol message before the second downlink control message based on theassigned first and second indexes.

Embodiments of the present disclosure further include an apparatuscomprising means for receiving a multicast downlink control message to aplurality of wireless communications devices including the apparatusaccording to an aggregation level from an access point. The apparatusfurther comprises means for extracting a resource allocation by theaccess point for the apparatus from among a plurality of resourceallocations to the plurality of wireless communications devices in themulticast downlink control message. The apparatus further compriseswherein the aggregation level is one from among a plurality of differentaggregation levels.

The apparatus further includes means for accessing a bitmap having aplurality of bits, wherein each bit from among the plurality of bitscorresponds to a different resource and an asserted bit in a subset ofasserted bits from the plurality of bits corresponds to the resourceallocation for the apparatus. The apparatus further includes means foraccessing a field in the multicast downlink control message, means forlocating an identifier associated with the apparatus from among a listof identifiers, and means for determining an order value associated withthe located identifier. The apparatus further includes means foraccessing an array comprising a plurality of array elements, each arrayelement being identified in the array by an index value, means forsearching for the determined order value in the array, and means foridentifying at least one index value corresponding to at least one arrayelement in which the determined order value is located. The apparatusfurther includes means for determining which at least one asserted bitfrom among the subset of asserted bits corresponds to the at least oneidentified index value, and means for determining the resourceallocation identified by the at least on asserted bit located by the atleast one identified index value. The apparatus further includes whereinthe multicast downlink control message comprises a second multicastdownlink control message, the aggregation level comprises a secondaggregation level, and the plurality of wireless communications devicecomprises a second plurality of wireless communications devices. Theapparatus further includes means for receiving, prior to the secondmulticast downlink control message, a first multicast downlink controlmessage from the access point according to a first aggregation level,and means for accessing, by the wireless communications device, a firstbitmap having a first plurality of bits from the first multicastdownlink control message, the bitmap accessed from the second multicastdownlink control message comprising a second bitmap having a secondplurality of bits. The apparatus further includes wherein each bit fromamong the first plurality of bits corresponds to a different resourcethat provides resource allocations to a first plurality of wirelesscommunications devices other than the wireless communications device.The apparatus further includes wherein an amount of the first pluralityof bits equals an amount of the second plurality of bits. The apparatusfurther includes wherein an amount of the first plurality of bits isgreater than an amount of the second plurality of bits, the length ofthe second plurality of bits having been reduced by removal of bitpositions in the second plurality of bits that correspond to differentresources represented by a subset of assigned bits in the first bitmap.The apparatus further includes means for identifying the subset ofassigned bits in the first bitmap, means for reconstructing the secondbitmap to have a same number of bits as the first bitmap based on theidentified subset of assigned bits in the first bitmap, and means fordetermining the resource allocation based on the reconstructed secondbitmap. The apparatus further includes means for listening for the firstmulticast downlink control message at an assigned first index in adownlink control channel, and means for listening for the secondmulticast downlink control message at an assigned second index in thedownlink control channel, the second index being after the first index.

As those of some skill in this art will by now appreciate and dependingon the particular application at hand, many modifications, substitutionsand variations can be made in and to the materials, apparatus,configurations and methods of use of the devices of the presentdisclosure without departing from the spirit and scope thereof. In lightof this, the scope of the present disclosure should not be limited tothat of the particular embodiments illustrated and described herein, asthey are merely by way of some examples thereof, but rather, should befully commensurate with that of the claims appended hereafter and theirfunctional equivalents.

What is claimed is:
 1. A method, comprising: generating, by an accesspoint, a first downlink control message comprising a first set ofresource allocations to a first plurality of wireless communicationsdevices based on the first plurality of wireless communications devicesbeing assigned to a first aggregation level; generating, by the accesspoint, a second downlink control message comprising a second set ofresource allocations to a second plurality of wireless communicationsdevices based on the second plurality of wireless communications devicesbeing assigned to a second aggregation level that is different from thefirst aggregation level; and transmitting, from the access point, thefirst downlink control message to the first plurality of wirelesscommunications devices and the second downlink control message to thesecond plurality of wireless communications devices.
 2. The method ofclaim 1, further comprising: including, by the access point, a firstbitmap having a first plurality of bits in the first downlink controlmessage, wherein each bit from among the first plurality of bitscorresponds to a different resource and an asserted bit in the firstbitmap corresponds to a resource allocation from among the first set ofresource allocations; and including, by the access point, a secondbitmap having a second plurality of bits in the second downlink controlmessage, wherein each bit from among the second plurality of bitscorresponds to a different resource and an asserted bit in the secondbitmap corresponds to a resource allocation from among the second set ofresource allocations.
 3. The method of claim 2, further comprising:including, by the access point, a first array having a first totalnumber of array elements in the first downlink control message, thefirst total number of array elements equaling a total number of assignedbits from among the first plurality of bits in the first bitmap, eacharray element identifying a wireless communications device from thefirst plurality of wireless communications devices; and including, bythe access point, a second array having a second total number of arrayelements in the second downlink control message, the second total numberof array elements equaling a total number of assigned bits from amongthe second plurality of bits in the second bitmap, each array elementidentifying a wireless communications device from the second pluralityof wireless communications devices.
 4. The method of claim 3, furthercomprising: including, by the access point, a first field in the firstdownlink control message, the first field comprising a first identifierin a list of identifiers for the first plurality of wirelesscommunications devices; and including, by the access point, a secondfield in the second downlink control message, the second fieldcomprising a second identifier in a list of identifiers for the secondplurality of wireless communications devices.
 5. The method of claim 4,further comprising: placing, by the access point, the first identifierin a position in the list of the first field that has a first ordervalue, wherein each position in the list of identifiers in the firstfield corresponds to a different order value; and placing, by the accesspoint, the first order value in at least one array element of the firstarray identifying the wireless communications device from the firstplurality of wireless communications devices that identifies at leastone assigned bit in the first bitmap that corresponds to at least oneresource allocation from among the first set of resource allocations. 6.The method of claim 2, wherein an amount of the first plurality of bitsis greater than an amount of the second plurality of bits.
 7. The methodof claim 6, wherein the first plurality of bits comprises a subset ofassigned bits to at least one wireless communications device from amongthe first plurality of wireless communications devices, the methodfurther comprising: reducing, by the access point, a length of thesecond bitmap by removing bit positions from the second bitmap thatcorrespond to the first set of resource allocations represented by thesubset of assigned bits in the first bitmap, wherein the secondplurality of wireless communications devices determine the second set ofresource allocations by reconstructing the second bitmap to have a samenumber of bits as the first bitmap after obtaining the subset ofassigned bits from the first bitmap.
 8. The method of claim 1, furthercomprising: assigning, by the access point, the first downlink controlmessage to a first index in a downlink control channel; assigning, bythe access point, the second downlink control message to a second indexin the downlink control channel, the second index being higher than thefirst index; and transmitting, by the access point, the first downlinkcontrol message before the second downlink control message based on theassigned first and second indexes.
 9. A method, comprising: receiving,at a wireless communications device, a multicast downlink controlmessage to a plurality of wireless communications devices including thewireless communications device according to an aggregation level from anaccess point; and extracting, by the wireless communications device, aresource allocation by the access point for the wireless communicationsdevice from among a plurality of resource allocations to the pluralityof wireless communications devices in the multicast downlink controlmessage, wherein the aggregation level is one from among a plurality ofdifferent aggregation levels, the resource allocation based on thewireless communications device being assigned to the aggregation level.10. The method of claim 9, wherein the extracting further comprises:accessing, by the wireless communications device, a bitmap having aplurality of bits, wherein each bit from among the plurality of bitscorresponds to a different resource and an asserted bit in a subset ofasserted bits from the plurality of bits corresponds to the resourceallocation for the wireless communications device.
 11. The method ofclaim 10, wherein the extracting further comprises: accessing, by thewireless communications device, a field in the multicast downlinkcontrol message; locating, by the wireless communications device, anidentifier associated with the wireless communications device from amonga list of identifiers; and determining, by the wireless communicationsdevice, an order value associated with the located identifier.
 12. Themethod of claim 11, wherein the extracting further comprises: accessing,by the wireless communications device, an array comprising a pluralityof array elements, each array element being identified in the array byan index value; identifying, by the wireless communications device, atleast one index value corresponding to at least one array element inwhich the determined order value is located; determining, by thewireless communications device, the asserted bit from among the subsetof asserted bits that corresponds to the at least one identified indexvalue; and determining, by the wireless communications device, theresource allocation identified by the asserted bit located by the atleast one identified index value.
 13. The method of claim 10, whereinthe multicast downlink control message comprises a second multicastdownlink control message, the aggregation level comprises a secondaggregation level, and the plurality of wireless communications devicecomprises a second plurality of wireless communications devices, themethod further comprising: receiving, prior to the second multicastdownlink control message, a first multicast downlink control messagefrom the access point according to a first aggregation level; andaccessing, by the wireless communications device, a first bitmap havinga first plurality of bits from the first multicast downlink controlmessage, the bitmap accessed from the second multicast downlink controlmessage comprising a second bitmap having a second plurality of bits,wherein each bit from among the first plurality of bits corresponds to adifferent resource that provides resource allocations to a firstplurality of wireless communications devices other than the wirelesscommunications device.
 14. The method of claim 13, wherein an amount ofthe first plurality of bits is greater than an amount of the secondplurality of bits, the amount of the second plurality of bits havingbeen reduced by removal of bit positions in the second plurality of bitsthat correspond to different resources represented by a subset ofassigned bits in the first bitmap.
 15. The method of claim 14, furthercomprising: identifying, by the wireless communications device, thesubset of assigned bits in the first bitmap; reconstructing, by thewireless communications device, the second bitmap to have a same numberof bits as the first bitmap based on the identified subset of assignedbits in the first bitmap; and determining, by the wirelesscommunications device, the resource allocation based on thereconstructed second bitmap.
 16. An apparatus, comprising: a processorconfigured to: generate a first downlink control message comprising afirst set of resource allocations to a first plurality of wirelesscommunications devices based on the first plurality of wirelesscommunications devices being assigned to a first aggregation level; andgenerate a second downlink control message comprising a second set ofresource allocations to a second plurality of wireless communicationsdevices based on the second plurality of wireless communications devicesbeing assigned to a second aggregation level that is different from thefirst aggregation level; and a transceiver configured to transmit thefirst downlink control message to the first plurality of wirelesscommunications devices and the second downlink control message to thesecond plurality of wireless communications devices.
 17. The apparatusof claim 16, wherein the processor is further configured to: include afirst bitmap having a first plurality of bits in the first downlinkcontrol message, wherein each bit from among the first plurality of bitscorresponds to a different resource and an asserted bit in the firstbitmap corresponds to a resource allocation from among the first set ofresource allocations; and include a second bitmap having a secondplurality of bits in the second downlink control message, wherein eachbit from among the second plurality of bits corresponds to a differentresource and an asserted bit in the second bitmap corresponds to aresource allocation from among the second set of resource allocations.18. The apparatus of claim 17, wherein the processor is furtherconfigured to: include a first array having a first total number ofarray elements in the first downlink control message, the first totalnumber of array elements equaling a total number of assigned bits fromamong the first plurality of bits in the first bitmap, each arrayelement identifying a wireless communications device from the firstplurality of wireless communications devices; and include a second arrayhaving a second total number of array elements in the second downlinkcontrol message, the second total number of array elements equaling atotal number of assigned bits from among the second plurality of bits inthe second bitmap, each array element identifying a wirelesscommunications device from the second plurality of wirelesscommunications devices.
 19. The apparatus of claim 18, wherein theprocessor is further configured to: include a first field in the firstdownlink control message, the first field comprising a first identifierin a list of identifiers for the first plurality of wirelesscommunications devices; and include a second field in the seconddownlink control message, the second field comprising a secondidentifier in a list of identifiers for the second plurality of wirelesscommunications devices.
 20. The apparatus of claim 19, wherein theprocessor is further configured to: place the first identifier in aposition in the list of the first field that has a first order value,wherein each position in the list of identifiers in the first fieldcorresponds to a different order value; and place the first order valuein at least one array element of the first array identifying thewireless communications device from the first plurality of wirelesscommunications devices that identifies at least one assigned bit in thefirst bitmap that corresponds to at least one resource allocation fromamong the first set of resource allocations.
 21. The apparatus of claim17, wherein an amount of the first plurality of bits is greater than anamount of the second plurality of bits.
 22. The apparatus of claim 21,wherein the first plurality of bits comprises a subset of assigned bitsto at least one wireless communications device from among the firstplurality of wireless communications devices, the processor beingfurther configured to: reduce a length of the second bitmap by removingbit positions from the second bitmap that correspond to the first set ofresource allocations represented by the subset of assigned bits in thefirst bitmap, wherein the second plurality of wireless communicationsdevices determine the second set of resource allocations byreconstructing the second bitmap to have a same number of bits as thefirst bitmap after obtaining the subset of assigned bits from the firstbitmap.
 23. The apparatus of claim 16, wherein: the processor is furtherconfigured to assign the first downlink control message to a first indexin a downlink control channel, the processor is further configured toassign the second downlink control message to a second index in thedownlink control channel, the second index being higher than the firstindex, the transceiver is further configured to transmit the firstdownlink control message before the second downlink control messagebased on the assigned first and second indexes, and the apparatuscomprises an access point and the wireless communications devices eachcomprise a user equipment.
 24. An apparatus, comprising: a transceiverconfigured to receive a multicast downlink control message to aplurality of wireless communications devices including the apparatusaccording to an aggregation level from an access point; and a processorconfigured to extract a resource allocation by the access point for theapparatus from among a plurality of resource allocations to theplurality of wireless communications devices in the multicast downlinkcontrol message, wherein the aggregation level is one from among aplurality of different aggregation levels, the resource allocation basedon the apparatus being assigned to the aggregation level.
 25. Theapparatus of claim 24, wherein the processor is further configured to:access a bitmap having a plurality of bits, wherein each bit from amongthe plurality of bits corresponds to a different resource and anasserted bit in a subset of asserted bits from the plurality of bitscorresponds to the resource allocation for the apparatus.
 26. Theapparatus of claim 25, wherein the processor is further configured to:access a field in the multicast downlink control message; locate anidentifier associated with the apparatus from among a list ofidentifiers; and determine an order value associated with the locatedidentifier.
 27. The apparatus of claim 26, wherein the processor isfurther configured to: access an array comprising a plurality of arrayelements, each array element being identified in the array by an indexvalue; identify at least one index value corresponding to at least onearray element in which the determined order value is located; determinethe asserted bit from among the subset of asserted bits that correspondsto the at least one identified index value; and determine the resourceallocation identified by the asserted bit located by the at least oneidentified index value.
 28. The apparatus of claim 25, wherein: themulticast downlink control message comprises a second multicast downlinkcontrol message, the aggregation level comprises a second aggregationlevel, and the plurality of wireless communications device comprises asecond plurality of wireless communications devices, the transceiver isfurther configured to receive, prior to the second multicast downlinkcontrol message, a first multicast downlink control message from theaccess point according to a first aggregation level, the processor isfurther configured to access a first bitmap having a first plurality ofbits from the first multicast downlink control message, the bitmapaccessed from the second multicast downlink control message comprising asecond bitmap having a second plurality of bits, and each bit from amongthe first plurality of bits corresponds to a different resource thatprovides resource allocations to a first plurality of wirelesscommunications devices other than the apparatus.
 29. The apparatus ofclaim 28, wherein an amount of the first plurality of bits is greaterthan an amount of the second plurality of bits, the amount of the secondplurality of bits having been reduced by removal of bit positions in thesecond plurality of bits that correspond to different resourcesrepresented by a subset of assigned bits in the first bitmap.
 30. Theapparatus of claim 28, wherein the processor is further configured to:identify the subset of assigned bits in the first bitmap; reconstructthe second bitmap to have a same number of bits as the first bitmapbased on the identified subset of assigned bits in the first bitmap; anddetermine the resource allocation based on the reconstructed secondbitmap.